1. Field of the Invention
The present invention relates to a vehicle motion control device to control behaviors of a vehicle by operating a required yaw moment.
2. Description of the Related Art
Recently, a vehicle motion control device to control behaviors of a vehicle includes one to operate a yaw moment required for controlling the vehicle, and sets controllable variables according to the value of the operated yaw moment. Such a vehicle motion control device to perform the control according to the yaw moment, such as the vehicle motion control device employing the “steering angle feedforward+yaw rate feedback” control, is effective for enhancement of maneuverability on a high μ road (which represents a road surface having a high coefficient of friction). On the other hand, when the vehicle is traveling on a low μ road (a low coefficient of friction), excessive turning moment is added to possibly promote spin trend of the vehicle.
Further, different from the above vehicle motion control device to perform the control according to the yaw moment, various kinds of vehicle motion control devices to control behaviors of the vehicle by setting the controllable variables according to the coefficient of friction μ on the road (hereinafter referred to as road friction μ) have been proposed such as those disclosed in Japanese Unexamined Patent Application Publication No. 11-59216.
The technology disclosed in the above-described Japanese Unexamined Patent Application Publication No. 11-59216 realizes optimum control not only on the high μ road, but also on the low μ road.
However, problems occur, in that responsiveness to estimate the road friction μ is delayed, and abrupt change of road surfaces or the like cannot be coped with in excellent response.
The present invention is achieved in light of the above circumstances.